You can wait for D7100 reviews, they'll be coming in shortly I'm sure. Or you can wait for a D400, which might be a very long wait of course.

D7000/7100 body is much more similar to the D90 body, although if you get the grip, it will feel more solid. It also has many features D90 doesn't have, e.g. Ai lens compatibility and AF fine tune, which are D300 grade features. D7100 will also have probably the best (or at least the newest) high level DX sensor.

But, if you are wed to a D300 type body, there is no substitute. D300 body is perfect IMO, and whether there will be another DX body like that is anyone's guess. I also don't believe that D300 sensor is behind D90 in a substantial way, but it is certainly behind D7000 for low light use. On the other hand, D300 color transmission in good light is superior to D7000 from my point of view.

Perhaps we all just have to accept that there is no perfect camera for all people and all circumstances. I like D300 very much indeed, it feels just right in my hands with or without the grip, and I really enjoy its ergonomics, responsiveness, and control layout, but I only use it in relatively good light.

Thanks Vray, I'd love to wait but realistically I don't think the replacement D400/s will come this year, maybe towards the end when all the D7100 flurry settles but perhaps early 2014. But still, it would be out of my immediate price range at the moment. D300s is looking better and better. I normally don't shoot over 1600 and that's rare on the D90.

One thing you may consider is that I heard on this forum that D300s and D300 do not render colors the same way, and D300s might be closer to D7000 (i.e. a bit worse by implication). I only have experience with D300, so can't speak for this issue from first hand experience, also don't know how picky you might be in this regard.